motor noise?

6 replies to this topic
  • bluerider450

Posted October 09, 2004 - 11:20 AM


i bought a 2004 yamaha yz450f a few months ago and i was just woundering do your guys motors make alot of noise around the valve piston area?

  • cowboyona426

Posted October 09, 2004 - 11:51 AM


Yes, they tend to be kind of noisy, especially if you are used to pingers.

  • RCH_VisualMedia

Posted October 09, 2004 - 11:52 AM


Yes they do make noise from the top end of the bike. Depending on the type of oil I used, it would vary in loudness.

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  • bluerider450

Posted October 09, 2004 - 11:53 AM


so its not bad? just the vlaves working

  • cowboyona426

Posted October 09, 2004 - 11:54 AM


Yep, no worries :cry:

  • grayracer513

Posted October 09, 2004 - 02:59 PM


Remeber, there's a lot stuff moving parts moving around in there that you're not used to. Another thing that makes it noisier is that it fires half as often as a smudge pot. This means that at low speeds, idling in neutral, it fires, slaps all the slack out of the valve train, clutch, and transmission, and then comes crashing up against its own compression stroke. When it does that, it looses 50-200 rpm almost instantly. All those moving parts are like people standing up in a bus that just jammed on its brakes. Then, right after that, it fires again.

Another thing that happens is that at idle speeds, the cam assemblies tend to get driven by the valve springs as they rotate past the full open postion. This puts a whipping action into the cam chain, but it disappears as the engine speeds up a little.

Check this out. With your bike idling in neutral, pull the clutch in and see how much quieter it gets. You'll get used to it. :cry:

  • bluerider450

Posted October 11, 2004 - 08:28 AM


yeah i noticed that when i pull in the clutch i was just making sure it wasnt anything bad and seeing htis is a post for the bike i figured alot of you guys would have answers thanks

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